Oribasius was a compiler of existing knowledge rather than an original writer. His output was immense; he compiled the Synagoge, an encyclopedic digest of medicine, hygiene, therapeutics, and surgery from Hippocrates to his own times, in 70 volumes. The unwieldiness of the work was probably the reason why he also wrote a synopsis of it. Only 17 volumes survived. Vols. 5 & 6 were completed and issued by Auguste Molinier after the death of Bussemaker and Daremberg. Digital facsimiles of the set from Google Books at this link.